In the face of the riots, the beleaguered police are being bombarded as much with advice as they are with half-bricks and bottles. So what are the options being considered and would they really help to restore order to the streets?

The curfew

The aim would be to keep as many people off the street as possible to allow police to concentrate on picking off the trouble-makers. The acting Met commissioner, Tim Godwin, has called for a "voluntary" curfew imposed by local communities. The reality is that, voluntary or compulsory, it would be almost impossible to impose and to whom would it apply – tourists? Night bus drivers? Cleaners? How would an overstretched force decide whom to challenge?

The water cannon

This has been suggested by Patrick Mercer, a Conservative MP and former army officer, on the grounds that it has been successfully deployed in Northern Ireland. The home secretary, Theresa May, has been adamant – so far – that it will not be deployed. The main reason for using it is that it can disperse crowds without causing serious injury. The arguments against are that there are few Met officers trained in using it and that, at the current rate of spiralling violence, it would be impossible to deploy effectively. Water cannon has mostly been used in dispersing people in contained spaces, not across a whole city.

The rubber or plastic bullet

Again, this is used in Northern Ireland and credited with dispersing crowds without fatalities. The Met's deputy assistant commissioner, Steve Kavanagh, has said that baton rounds – plastic bullets – could now be used: "If we need to, we will do so." But shots to the head from close range can kill. Again, as with water cannon, the police would struggle to get officers trained in the use of them to the scenes of violence. One problem is that both water cannon and plastic bullets might merely heighten the levels of excitement for the committed rioter and looter. And is Northern Ireland really an example of how to keep the peace?

The army

The doomsday scenario for London as it prepares for the Olympics. The army has been deployed in a civilian role during firefighters' strikes, but putting young squaddies up against their inner-city contemporaries would be a recipe for urban disaster on a scale more suitable for a graphic novel than reality.

Exactly 100 years ago, a home secretary was under pressure from the media and fellow politicians to act decisively against outrage on the streets of London. The perpetrators then were, at least, identifiable and containable and had been tracked down to Sidney Street in the East End. The police had the miscreants – Latvian anarchists wanted for murder – surrounded in a house but the home secretary, Winston Churchill, called in the Scots Guards from the Tower of London and, dressed in top hat and astrakhan collar greatcoat, directed operations. The house caught fire and Churchill prevented the fire brigade from dousing the flames so the men inside were burned to death. "I thought it better to let the house burn down rather than spend good British lives in rescuing those ferocious rascals," wrote Churchill.

We will not see May at the head of a column of foot-soldiers tomorrow but she may now reckon that a demoralised police service that had already warned her it was under-strength may need more than water cannon and curfews if it is to bring calm to the city on a regular basis. The start of the riots is attributed to heavy-handed policing and lack of information. Upping the level of force could be just as counter-productive.